A portable language for scientific computations often credited with introducing many of the common syntax and structured programming conventions found in most modern programming languages.
ALGOL 58 was also known as the International Algebraic Language.

ALGOL 60 (AlgolSixty) was block-structured, nested, recursive and free form. These are features which the other language for scientific computations used at this time, Fortran [FortranLanguage], lacked. ALGOL 60 was also the first language to be described in BackusNaurForm. It provided CallByValue and CallByName semantics, but no support for user-defined types or I/O.

ALGOL 60 was small and elegant (see TonyHoareOnAlgolSixty), ALGOL 68 was big and complex (and rumored not to be implementable). (Falsely rumoured, it would seem, as there are today two different Open Source implementations available.)

Why did it fail (relative speaking) despite having many of the modern features we've grown to like? Ahead of its time? Too expensive? In some ways it shares a similar fate to SmallTalk: inspired many ideas and later languages, but failed to catch on by itself. (Lisp almost has this distinction, but remains a very popular "hobby" language.)

In a way it succeeded at its original purpose, as most academic descriptions of algorithms still use pseudocode that looks more like Algol than anything else. Lack of standardized I/O and difficult-to-implement CallByName semantics might lave played a role in its fade from physical use.